Tempo Distortion #4 is a conceptual study in simultaneously occurring patterns in different tempi for solo marimba and pre-recorded and processed marimba sounds. The marimba part is a continuous stream of notes consisting of thirteen repeating patterns that shift gradually in tempo from fast to medium tempo and back to fast. Each of the marimbas patterns follows a dynamic effect of soft (mp) to loud (ff) to soft (mp). The pre-recorded track was assembled from marimba samples recorded by Dave Gerhart. The samples were manipulated and transformed through digital looping and pitch shifting techniques and then layered to create a continuum of phasing rhythmic structures. The combination of the live performance elements and recorded sounds results in a sonic landscape of shifting tempo ambiguities and overlapping textural densities.